Neither Aperture or Lighroom are actually good enough to be a complete filing system. They are RAW developers with a flawed library tacked on. Extensis is however designed to organise data, but where Aperture Bridge and LR should score higher is integration of filing and then doing work on the images you use programme to find.
Which is my point really, have a filing system that works anywhere with any software, do not buy a programme to do your filing for you as otherwise you are digging a big hole for yourself when the programme gets replaced by something else - which when you are talking about filing, it has to last for 30/40/50 yrs and that's just your lifetime. Software comes and goes as do businesses.